title: Changes in the development of striatum are involved in repetitive behavior in autism.
abstract: BACKGROUND
  Repetitive behavior is a core feature of autism and has been linked to differences in striatum. In addition, the brain changes associated with autism appear to vary with age. However, most studies investigating striatal differences in autism are cross-sectional, limiting inferences on development. In this study, we set out to 1) investigate striatal development in autism, using a longitudinal design; and 2) examine the relationship between striatal development and repetitive behavior.
  
  
  METHODS
  We acquired longitudinal structural magnetic resonance imaging scans from 86 individuals (49 children with autism, 37 matched control subjects). Each individual was scanned twice, with a mean scan interval time of 2.4 years. Mean age was 9.9 years at time 1 and 12.3 years at time 2. Striatal structures were traced manually with high reliability. Multivariate analyses of variance were used to investigate differences in brain development between diagnostic groups. To examine the relationship with behavior, correlations between changes in brain volumes and clinical measures were calculated.
  
  
  RESULTS
  Our results showed an increase in the growth rate of striatal structures for individuals with autism compared with control subjects. The effect was specific to caudate nucleus, where growth rate was doubled. Second, faster striatal growth was correlated with more severe repetitive behavior (insistence on sameness) at the preschool age.
  
  
  CONCLUSIONS
  This longitudinal study of brain development in autism confirms the involvement of striatum in repetitive behavior. Furthermore, it underscores the significance of brain development in autism, as the severity of repetitive behavior was related to striatal growth, rather than volume per se.
authors.affiliation: NICHE Lab, Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Center Utrecht, The Netherlands. Electronic address: m.langen@umcutrecht.nl.
authors.forename: Marieke
authors.initials: M
authors.lastname: Langen
authors.affiliation: NICHE Lab, Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Center Utrecht, The Netherlands.
authors.forename: Dienke
authors.initials: D
authors.lastname: Bos
authors.affiliation: NICHE Lab, Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Center Utrecht, The Netherlands.
authors.forename: Siri D S
authors.initials: SD
authors.lastname: Noordermeer
authors.affiliation: NICHE Lab, Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Center Utrecht, The Netherlands.
authors.forename: Hilde
authors.initials: H
authors.lastname: Nederveen
authors.affiliation: NICHE Lab, Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Center Utrecht, The Netherlands.
authors.forename: Herman
authors.initials: H
authors.lastname: van Engeland
authors.affiliation: NICHE Lab, Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Center Utrecht, The Netherlands.
authors.forename: Sarah
authors.initials: S
authors.lastname: Durston
mesh_terms: D000293:Adolescent; D001321:Autistic Disorder / Q000473:pathology*; D001921:Brain / Q000254:growth & development / Q000473:pathology; D002648:Child; D003342:Corpus Striatum / Q000254:growth & development* / Q000473:pathology*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D015999:Multivariate Analysis; D009929:Organ Size; D013239:Stereotyped Behavior
keywords: Autism; brain development; corticostriatal circuitry; insistence on sameness; repetitive behavior; striatum